Novavax Vs. Pfizer Vs. Moderna: How COVID-19 Vaccines Stack Up

It was "better late than never" for Novavax, Inc. NVAX, as the biopharma finally got around to announcing interim results from the U.S. and Mexico leg of the Phase 3 study of NVX-CoV2371, its vaccine candidate against the novel coronavirus.

Here's a comparative perspective of the vaccine candidates from Novavax, and the frontrunners, namely Pfizer Inc. PFE-BioNTech SE BNTX and Moderna, Inc. MRNA, both of which have authorized vaccines in the market.

Vaccine Type: Novavax's NVX-CoV2371 is a recombinant nano-particle protein-based COVID-19 vaccine that is packaged with the company's proprietary Matrix-M adjuvant.

The Pfizer-BioNTech and Moderna products are mRNA vaccines, or modern vaccines that work by using a genetic code called mRNA that instructs our immune cells to make spike protein, which is found on the surface of the virus that causes COVID-19.

This spike protein, though harmless, is capable of triggering our immune system to produce antibodies that offer protection against future infection.

Novavax's vaccine is a protein adjuvant that contains the spike protein of the coronavirus itself, but formulated as a nanoparticle that cannot cause disease. The injected vaccine then stimulates the immune system to produce antibodies and T-cell immune responses.

The Vaccine Doses: The vaccines from each of the three companies require two doses. Each dose consists of 30 mcg for Pfizer and 100 mcg for Moderna, while for Novavax, each vaccine dose consists of 5 mcg of NVX-CoV2371 and 50 mcg of Matrix-M1 adjuvant that are co-formulated.

The interval between the two doses — the priming and booster dose — is 21 days each for Pfizer and Novavax and 28 days for Moderna.

The Target Population: The original late-stage trial of Pfizer-BioNTech evaluated the vaccine in participants ages 16 years and older. The trial enrolled 43,448 participants.

Moderna's Phase 3 COVE study enrolled 30,000 participants ages 18 years and up. 

Since then, these two companies have obtained authorizations for their respective vaccines to be used in adolescents.

Both companies have also initiated studies in the pediatric population.

Novavax's study enrolled 29,960 participants 18 years of age and older across 119 sites in the U.S. and Mexico. The placebo-controlled portion of PREVENT-19 continues in adolescents from 12 to less than 18 years of age and recently completed enrollment with 2,248 participants.

Vaccine Logistics: Pfizer recently secured FDA authorization for storing undiluted, thawed vaccine vials in the refrigerator at 2°C to 8°C for up to one month.

Previously, thawed, undiluted vaccine vials could be stored in the refrigerator for up to five days. Moderna's vaccine can be stored refrigerated between 2° and 8°C for up to 30 days prior to first use.

NVX-CoV2373 is stored and stable at 2°- 8°C, allowing the use of existing vaccine supply chain channels for its distribution. It is packaged in a ready-to-use liquid formulation in 10-dose vials.

Related Link: The Week Ahead In Biotech: Takeda, Blueprint Medicines, Orphazyme, Eton On The Radar Ahead Of FDA Decisions, IPOs

Vaccine Efficacy: Interim data from Pfizer-BioNTech's Phase 3 trials released in December showed the vaccine was well-tolerated and demonstrated 95% efficacy in preventing COVID-19 in those without prior infection seven days or more after the second dose. Updated top-line results released for up to six months after the second dose confirmed efficacy at 91.3%.

The vaccine was found 100% effective against severe disease as defined by the U.S. Centers for Disease Control and Prevention, and 95.3% effective against severe COVID-19 as defined by the FDA. It was also proved effective against the U.K. strain in lab studies.

Moderna's vaccine showed efficacy of 94.1% against COVID-19. The company announced in May initial data from its Phase 2 study showing that a single 50 mcg dose of mRNA-1273 or mRNA-1273.351 given as a booster to previously vaccinated individuals increased neutralizing antibody titer responses against SARS-CoV-2 and two variants of concern, B.1.351, first identified in South Africa, and P.1, first identified in Brazil.

Novavax's investigational vaccine demonstrated 100% protection against moderate and severe disease not involving variants of concern or variants of interest.

Against variants of concern and variants of interest, the efficacy was 93.2% and in high-risk populations, defined as over 65 or under 65 years with certain comorbidities or having circumstances with frequent COVID-19 exposure, the efficacy was 91%.

Overall efficacy was 90.4%, meeting the primary endpoint.

Cantor Fitzgerald On Novavax's Vaccine: A differentiating factor for NVX-2373 is that it showed vaccine efficacy of 93.2% against VoC/VoI, which demonstrates protection across a broad range of SARS-CoV-2 strains, Cantor Fitzgerald analyst Charles Duncan said in a Monday morning note.

"Overall, these results enhance our conviction for a differentiated clinical and logistics profile from the SARS-CoV-2 vaccine candidate ‘2373," the analyst said.

Showing efficacy against new strains in two Phase 3 clinical trials, rather than extrapolating potential efficacy from a neutralizing antibody assay conducted in a petri dish, differentiates NVX-CoV2373 from other vaccines that have emergency use authorization, he said. 

This profile, according to Cantor reduces regulatory/ commercial risk for the ‘2373 SARS-CoV-2 prophylactic vaccine candidate and, with positive Phase 3 data for NanoFlu reported in March 2020, should raise the profile for Novavax's platform as a whole.

Vaccine Safety Data: Pfizer-BioNTech's vaccine showed a favorable tolerability and safety profile, with the most common adverse events from BNT162b2 being transient, mild to moderate pain at the injection site, fatigue and headache, and these generally resolved within two days.

For Moderna, the most common adverse reactions included injection site pain, fatigue, myalgia, arthralgia, headache, and erythema/redness at the injection site. Solicited adverse reactions increased in frequency and severity in the mRNA-1273 group after the second dose.

Preliminary safety data from Novavax's trial showed the vaccine to be generally well-tolerated. Serious and severe adverse events were low in number and balanced between vaccine and placebo groups.
In assessing reactogenicity seven days after dose one and dose two, injection site pain and tenderness, generally mild to moderate in severity, were the most common local symptoms, lasting less than three days. Fatigue, headache and muscle pain were the most common systemic symptoms, lasting less than two days.

Related Link: Attention Biotech Investors: Mark Your Calendar For June PDUFA Dates